How to Add Birthdays to an iPhone Calendar

Open the Contacts app.

You can add new birthdays to your calendar in your iPhone's Contacts app. Start by tapping the gray address book icon with multicolored tabs. You’ll usually find it on the home screen.

Select a contact.

Tap the contact whose birthday you want to add. This opens the contact’s details. If the person is not one of your phone contacts, you’ll have to add them first.

Tap "Edit" on the contact.

You'll see Edit at the top-right corner. Now you can edit all details of the contact.

Tap "+ add birthday."

You might have to scroll down a little bit to see this option. The date scroll will appear at the bottom of the screen.

Enter the person's birthdate.

Select the person’s birth date from the scrolls. Swipe down on the day, month, and year until the correct date appears in black at the center of the scroll.

Tap "Done" to save your changes.

Tap Done at the top-right corner. This saves this contact’s birthday.

Open your calendar.

Return to the home screen and open the Calendar. It’s the white icon with the current date inside.

Enable the Birthdays calendar.

If the Birthdays calendar isn't enabled, you won't see your contacts birthdays. To enable the calendar: Tap Calendars at the bottom. Add a checkmark next to "Birthdays." If there’s a check mark in its radio button, that means your contacts’ birthdays are set to appear in the calendar. If not, tap the radio button to add one.

Tap "Done."

Tap Done at the top-right corner. The contact’s birthday now appears on the calendar. You can verify by going to the date in the calendar—there will be a little present icon to indicate that it’s the person’s birthday.